The MP reads a maximum speed value for every different aircraft type from the Object_Specifications table (Speed field, measured in metres per hour). As compiled, this Speed field contains a representative maximum flight speed for the aircraft in clean test mode - this is a True Air Speed (TAS) - gleaned from a variety of sources. Advanced SEOW users are free to change these Speed values as they see fit.
However, prior to SEOW3.1.1, I had expected that speeds encoded in the mission files were also TAS speeds. Therefore I had written the MP to specify flight speeds to each waypoint as TAS. It seems that this is WRONG!
In fact, the speeds encoded in the mission files are Indicated Air Speeds (IAS), which are always slower than TAS, and slower by an increasing margin as altitude increases. The net effect of this is that commanders were specifying IAS speeds based on a range of speeds appropriate for the faster TAS range.
From SEOW3.1.1 onwards, the MP automatically applies a flat correction factor to the TAS maximum speed before presenting speeds to the commanders for adjustment. The correction factor is set in MP-Configuration.php:
Now, commanders can be assured that all aircraft speeds in the MP are expressed as IAS speeds. Of course the flat correction factor is a gross simplification - we could build altitude-dependent correction factors and altitude-dependent maximum speeds into SEOW, but this might not be worth the effort. Any feedback?$TASIASFactor=0.75;
Cheers,
4Shades
